To use a respiratory ventilator, a patient has to adapt or change his or her ingrained breathing pattern, as explained, e.g., in U.S. Pat. No. 3,991,304 to Hillsman, the disclosure of which is incorporated herein by reference. The Hillsman patent addresses this problem by providing a system which displays an ideal breathing pattern on a video screen, which can be watched and followed by the patient. But this is not a satisfactory solution, particularly since respiratory patients are often not able to see, or at least not able to respond well to visual stimuli. Also, the Hillsman approach does nothing to reduce anxiety and disorientation, which are the natural result of being connected to a ventilator.
Other related prior art patents include U.S. Pat. No. 2,771,069 to Baron, U.S. Pat. No. 2,821,189 to Hofmann, U.S. Pat. No. 3,403,674 to Alimanestiano, U.S. Pat. No. 3,547,106 to Bornmann, U.S. Pat. No. 3,552,388 to Zelenka, U.S. Pat. No. 3,730,173 to Deaton, U.S. Pat. No. 4,064,869 to Defares et al., and U.S. Pat. No. 4,984,568 to Persaud, the disclosures of which are incorporated herein by reference.
U.S. Pat. No. 2,771,069 to Baron discloses a bed which is pivoted in synchronization with a respiratory device to promote a desired respiration pattern. In operation, the head of the bed is positioned downwardly so that a patient can exhale air. When the bed is tilted up, air is inhaled by the patient. However, the system disclosed in the Baron patent is complicated and cumbersome, and it would increase a patient's anxiety and disorientation rather than promote a relaxed and ultimately fruitful response.
Similarly, the Defares patent discloses an apparatus for regulating breathing. The apparatus has a tone generator for producing audible tones for regulating the breathing patterns of a patient. The Defares device includes a sensor which is attached to a patient's chest containing a tube which is alternately expanded and contracted to the rhythm of the patient's breathing. When the breathing rhythm is out of synchronization with a clock control counter, a hyperventilation signal is produced which activates a generator. The generator tones are alternately progressively increased and decreased to produce two different tones signalling abnormal breathing. However, a recovering patient's responses to auditory tones may be severely limited by medication, causing an inability to concentrate. Additionally, noises made by other equipment might interfere with the patient's ability to hear tones.
The Bornmann patent discloses a device which imparts mechanical stimulation to arouse an infant which has stopped breathing. However, that mechanical stimulation fails to promote rhythmic breathing. The Hofmann patent discloses a respiration stimulation device where breathing rhythms are controlled by applying low frequency current to alternate muscle groups controlling the inspiration and exhalation muscles. The Deaton patent discloses a device for monitoring the respiration and/or heartbeat of a patient through any conventional device such as an apnea monitor. When respiration appears to be abnormal, a stream of pressurized air is directed against the patient's body. The Zelenka patent discloses a baby-patting machine. The Alimanestiano and Persaud patents disclose massaging devices.